The present invention relates in general to magneto-resistive random access memory (MRAM). More particularly, the present invention relates to selective growth of a seed layer for an MRAM cell to be provided with at least one magnetic tunnel junction (MTJ).
Data in MRAM is stored by magnetic storage elements. The elements are formed from ferromagnetic plates that each hold a magnetization and which are separated by a thin insulating layer. One of the two plates is provided as a permanent magnet that is set to a particular polarity (i.e., the fixed or reference layer) and the magnetization of the other plate can be changed to match that of an external field in order to store data (i.e., the free layer). This configuration is known as a magnetic tunnel junction (MTJ). A memory device can be built from a grid of MTJ “cells” where each cell includes multiple MTJs.